The Northumberland Strait vessel design is well proven for a variety of fishing activities. The freeboard of this type of vessel is such that once the vessel is heavily laden, the well deck and its draining scuppers are under water. As a consequence, this type of vessel is not well suited to carrying heavy loads. The vessel's centre of gravity was raised by the weight of the platform deck and the load upon it. Despite this, no professional advice had been sought for the design or construction of the platform deck, and no technical review or stability calculation had been carried out. The platform deck was braced from below (to the well deck) to support its weight and that of the load. The structure was also attached to the inner edge of the GRP gunwale, but this securing arrangement was not strong enough to withstand the various forces imposed upon it in service. Neither the owner/operator nor the charterer could provide an accurate assessment of the weight of the deck cargo. The centre of gravity of the load (and the consequential rise in the centre of gravity of the vessel) can only be approximated by calculation. However, the weight of the cargo and the platform increased the draught and reduced the freeboard to the point where the scuppers and the well deck were below water level. Consequently, the scuppers were plugged before departure to prevent an ingress of water. Any water shipped over the gunwale would therefore be retained on board. The resulting free surface effect and weight of retained water would have caused an additional, virtual rise of the vessel's centre of gravity. Combined with an already high centre of gravity, the free surface effect and the weight of the shifted cargo were sufficient to cause the vessel to capsize. Because the platform deck had been used successfully in the past, on another vessel, and on the WetN'WildII the day before the accident, it gave the operator a false sense of security. Consequently, the dangers associated with an improperly constructed and secured platform were not fully recognized by the crew. Since 30 July 1999, the Crewing Regulationsmade under the Canada Shipping Acthave required a Fishing Master, Class IV, certificate for vessels of 60 gross tons and over. The WetN'WildIImeasured 14.97 gross tons. Although the owner/operator held a certificate of competency as a Fishing Master, Class IV, the operation of a vessel of this size did not require this certificate. In the examination syllabus for this certificate there is no requirement that a candidate exhibit knowledge or understanding of stability. As the vessel was under 15 gross tons, the owner was not required by regulation to have his vessel inspected by Transport Canada; the vessel had not been voluntarily offered for inspection.Analysis The Northumberland Strait vessel design is well proven for a variety of fishing activities. The freeboard of this type of vessel is such that once the vessel is heavily laden, the well deck and its draining scuppers are under water. As a consequence, this type of vessel is not well suited to carrying heavy loads. The vessel's centre of gravity was raised by the weight of the platform deck and the load upon it. Despite this, no professional advice had been sought for the design or construction of the platform deck, and no technical review or stability calculation had been carried out. The platform deck was braced from below (to the well deck) to support its weight and that of the load. The structure was also attached to the inner edge of the GRP gunwale, but this securing arrangement was not strong enough to withstand the various forces imposed upon it in service. Neither the owner/operator nor the charterer could provide an accurate assessment of the weight of the deck cargo. The centre of gravity of the load (and the consequential rise in the centre of gravity of the vessel) can only be approximated by calculation. However, the weight of the cargo and the platform increased the draught and reduced the freeboard to the point where the scuppers and the well deck were below water level. Consequently, the scuppers were plugged before departure to prevent an ingress of water. Any water shipped over the gunwale would therefore be retained on board. The resulting free surface effect and weight of retained water would have caused an additional, virtual rise of the vessel's centre of gravity. Combined with an already high centre of gravity, the free surface effect and the weight of the shifted cargo were sufficient to cause the vessel to capsize. Because the platform deck had been used successfully in the past, on another vessel, and on the WetN'WildII the day before the accident, it gave the operator a false sense of security. Consequently, the dangers associated with an improperly constructed and secured platform were not fully recognized by the crew. Since 30 July 1999, the Crewing Regulationsmade under the Canada Shipping Acthave required a Fishing Master, Class IV, certificate for vessels of 60 gross tons and over. The WetN'WildIImeasured 14.97 gross tons. Although the owner/operator held a certificate of competency as a Fishing Master, Class IV, the operation of a vessel of this size did not require this certificate. In the examination syllabus for this certificate there is no requirement that a candidate exhibit knowledge or understanding of stability. As the vessel was under 15 gross tons, the owner was not required by regulation to have his vessel inspected by Transport Canada; the vessel had not been voluntarily offered for inspection. The WetN'WildIIwas engaged in an operation for which she had not been initially designed. The platform was not professionally designed or constructed, and no professional stability review had been sought, although the weight of the platform and load had raised the vessel's centre of gravity. The arrangement by which the platform was secured to the gunwales could not withstand the forces imposed by the weight of the cargo and the vessel's sea motions. With the scuppers plugged, water shipped onto the well deck was retained; the resulting free surface effect and weight further reduced vessel stability. Once the owner/operator turned the vessel towards the wharf at Lennox Island, the lower, starboard side of the vessel became the weather side and water was more readily shipped onto the well deck. The vessel was not inspected, nor was it required to have been. Neither the owner/operator nor the charterer knew the weight of the cargo loaded on board. Although not required for a vessel of this size, the owner/operator held a valid Fishing Master, Class IV, certificate of competency. In the examination syllabus for a Fishing Master, Class IV, there is no requirement to demonstrate knowledge of vessel stability. The lifejackets recovered after the sinking were not of an approved type nor were they worn.Findings The WetN'WildIIwas engaged in an operation for which she had not been initially designed. The platform was not professionally designed or constructed, and no professional stability review had been sought, although the weight of the platform and load had raised the vessel's centre of gravity. The arrangement by which the platform was secured to the gunwales could not withstand the forces imposed by the weight of the cargo and the vessel's sea motions. With the scuppers plugged, water shipped onto the well deck was retained; the resulting free surface effect and weight further reduced vessel stability. Once the owner/operator turned the vessel towards the wharf at Lennox Island, the lower, starboard side of the vessel became the weather side and water was more readily shipped onto the well deck. The vessel was not inspected, nor was it required to have been. Neither the owner/operator nor the charterer knew the weight of the cargo loaded on board. Although not required for a vessel of this size, the owner/operator held a valid Fishing Master, Class IV, certificate of competency. In the examination syllabus for a Fishing Master, Class IV, there is no requirement to demonstrate knowledge of vessel stability. The lifejackets recovered after the sinking were not of an approved type nor were they worn. While the WetN'WildIIwas en route to Bird Island, the platform on which the cargo was stowed collapsed, causing it to shift and the vessel to heel to starboard. With an already high centre of gravity, the effect of the shifted cargo, combined with the weight and free surface effect of water shipped and retained on deck, caused the WetN'WildIIto capsize and subsequently sink. Factors contributing to the occurrence were: the vessel was being used for a purpose for which she was not designed; the operator lacked knowledge of vessel stability, and had not sought a professional review of stability; the platform was inadequately secured to withstand operational forces; with the deck scuppers plugged, water shipped on board was retained on deck and the low side of the vessel was exposed to the weather.Causes and Contributing Factors While the WetN'WildIIwas en route to Bird Island, the platform on which the cargo was stowed collapsed, causing it to shift and the vessel to heel to starboard. With an already high centre of gravity, the effect of the shifted cargo, combined with the weight and free surface effect of water shipped and retained on deck, caused the WetN'WildIIto capsize and subsequently sink. Factors contributing to the occurrence were: the vessel was being used for a purpose for which she was not designed; the operator lacked knowledge of vessel stability, and had not sought a professional review of stability; the platform was inadequately secured to withstand operational forces; with the deck scuppers plugged, water shipped on board was retained on deck and the low side of the vessel was exposed to the weather.